Figure 1.

Acquisition of experimental body migration data in a motion capture laboratory: Markers were placed on the skin of subjects, as well as on the mattress. The location of each marker was recorded as the head of bed was elevated to either 45° or 65° inclination level. The red and green dots depict the location of the skin markers. The “trochanter migration” was defined along the length of the bed (x‐axis) and was calculated relative to the mattress as the difference between the initial and final spatial locations of the markers attached at the trochanter site